/*! \page FAQ FAQ

\section faq FAQ

\ref faq1

\subsection faq1 How do I choose the timestep?
<p>
In VMC, the only concern with the timestep is the time it takes to decorrelate
each point in the random walk.  There are two competing effects that prevent
this: 1) if the steps are too small, then the adjoining points are too close
and 2) if they are too large, then the rejection rate increases, causing a 
repetition of a point in the walk.  A general rule of thumb is to make the
acceptance ratio around 0.60, although the ideal number can change from system
to system.
</p>
<p>
In DMC, the propagator only works in short timesteps, so you should
choose the time step so that the acceptance ratio is roughly 0.99.  For 
very accurate calculations, more might be necessary; you may need to do
several calculations at different time steps to get a feel for the bias.
</p>

*/